So I bought TP-LINK Deco M5 3xKit and decided to use the Deco as my main router and Archer VR400 as modem only

I reseted Archer VR400 and created bridge connection, turned off the wifi and changed the IP to 192.168.0.1.

the router restarted and I managed to log into it through 192.168.0.1

Then I setup My Deco M5 using pppoe and got connected to the internet without a problem, my Deco IP is 192.168.1.1

Here the thing when I try to connect to 192.168.0.1. I get no response I tried http://192.168.0.1/ -  https://www.tplinkmodem.net/ -  http://tplinkwifi.net/

I connected my PC to VR400 through Ethernet directly and can't access the GUI at all.

You might be asking why do I want to login into VR400 if the Deco is connected to the internet and is working fine?

Well sometimes I want to check and troubleshoot my internet issues and Deco doesn't give any info regarding Downstream/upstream, line attenuation .. etc